An electrostatic charge, also known as an electrical charge or static charge, was the amount of energy which passed from one body to another, typically associated with the result of phaser energy, a transporter beam or a force field.
The Hur'q, after absconding with the mythical Sword of Kahless from Qo'noS in the 14th century, placed it behind a holographic wall with a force field emitting an electrostatic charge. It was not discovered until 2372. (DS9: "The Sword of Kahless")
In 2371, Lieutenant Jadzia Dax, while searching for the missing Major Kira Nerys, detected an electrostatic charge near the former Elemspur prison camp on Bajor. Commander Benjamin Sisko speculated that she could have been beamed away and kidnapped. Dax also surmised Kira could have been vaporized by a phaser as well, as an electrostatic charge could also be the result of a phaser hit. (DS9: "Second Skin")
Upon arriving in three different years: 1930, 1967 and 2048, Chief Miles O'Brien scanned for a residual electrostatic charge with his tricorder to try and locate the temporally displaced Benjamin Sisko, Jadzia Dax and Julian Bashir. O'Brien's tricorder failed in each year to find the electrostatic charge until on his last attempt, when he and Kira arrived in 2024 and O'Brien finally detected the charge. (DS9: "Past Tense, Part II")